Today, I'll be addressing this question: Is human nature constant, or can it be molded by culture and society? If it can be molded, can it be changed completely?
First off, I would say "human nature" is a sort of broad concept to describe with words like "constant". When we talk about things like "human nature", it's hard to define what is actually being referred to and where the lines are drawn. By asking whether or not human nature is a constant thing, we are asking whether or not we, as individuals, are all fundamentally the same. And to that, I'd argue that we are at our cores the same. In the very least, since we all have the same sort of brains, we all have the same sort of basic functions, so human behavior can generally be predicted.
This is, of course, bringing us to the age old question of nature versus nurture. Are we a product of ourselves or the environment we are put in? Must there be a dichotomy between the two? I think to answer this question one has to look no further than the many stories of reunited twins that were separated at birth. In many of the tales I've heard, these twins lead very similar lives to each other, yet there are always stark contrasts.
I'd also bring up two famous psychological studies to further expand on this: the Milgram experiment, and the Stanford prison experiment. I won't describe the details of either of these, but they are both very interesting and inform us a lot about human nature. In the Milgram experiment, participants were asked to punish people to the point where their morality warred with the orders they were given by an authority figure. People overwhelmingly did as they were told even when their ethics wanted otherwise. In the prison experiment, students were given "roles" to play, and they naturally acted the part to the point where it became unethical to continue, since the guards became aggressive and harsh and the prisoners became docile and obedient, even when both parties had the same level of authority in the real world.
All in all, the conclusion I would draw from this is that in the long term, we all behave similarly. Our genetic code and the personality we were born with dictates most of how we act in general, as a society. But in the short term, nurture dictates who we are in the moment. We are taught how to behave in certain situations, and we consciously use what we know to overcome certain obstacles. How we treat strangers, how we react to good and bad news, these are all things we are taught. But I believe our core personality and who we are under our level of conscious thought is something that is coded into our system, and no amount of education and learning will change who we are at the core.